Post on 20-Jan-2016
MODERN CLIMATE
AND HYDROLOGICAL CYCLE OF MARS.
A.V.Rodin, A.A.Fedorova, N.A.Evdokimova, A.V.Burlakov, O.I.Korablev 1Moscow Institute of Physics and Technology, Russia; Space Research Institute, Russia .
Contact: Alexander.Rodin@phystech.edu
Seasonal and latitudinal distribution of water vapor
Viking 1,2 MAWD
TES – 20-40 microns
1.38 μm
MY 27 SPICAM IR
Smith 2002-2008
Fedorova et al. 2006 Jakosky, Farmer 1984
Jakosky et al.1984-1995:
Titov, Houben Regolith matters
Clancy et al., 1996: Circulation affected by
Richardson, Wilson, 2003 orbit excentricity &
Montmessin et al., 2004 hemispheircal asymmetry
cloud microphysics matters
TES, PFS, OMEGA, SPICAM, MCS: search for zonal, seasonal and interannual variations
Mars Atmosphere General Circulation Model
•FMS dynamical core•Aerosol –consistent radiation•H2O cloud microphysics•11.5, kz=28
Ls = 270 z=5 km
GCM illustration of Clancy effect: aphelion-perihelion asymmetry
perihelion aphelion
Clancy et al., 1996, Montmessin et al, 2002
50 100 150 200 250 300 350-90
-60
-30
0
30
60
90
Water vapor, pr. m
Solar areocentric longitude
L
atitu
de
5
5
510
10
10
10
15
15
15
15
15
15
15
20
20
20
202
0
2020
25
25
25
25
3030
30
35
35
4045
50 60 65
Seasonal Mars water cycle: GCM results
Water vapor column distributions on Mars
imply significant zonal variations:Viking/MAWD (Fedorova et al., 2004, Pankine et al.,2009)
Ls = 20
Ls = 330Ls = 150
Ls = 90
MGCM simulations
Water vapor annual average:atmosphere-surface interactions
Water vapor column, pr. mExposure (days) of frost layer
exceeding 100 m
Mitrofanov et al., 2002
Antipodal maxima of bound water content
Annual average (contd.)H2O molecules number densityprovided T > 220 K
Cold trap: total time when T>30 Kand T > 200 K, days
Basilevsky et al., 2006, Nelli et al., 2006
Soil hydration: - significant latitudinal variations - no evident connection to the seasonal water cycle
Evdokimova et al., 2010
MGS/TES (Pankine et al.,2009)
MEX/SPICAM: Spatial distribution of water vapor summer in north hemisphere
Ls 95-120: 59 orbits from 72 orbits are presented
Fedorova et al, 2009
0
180
10
20
30
40
50
60
MGCM instant water vapor column: North hemisphere [pr. m]
0
180
0
100
200
Ls = 92
0
180
0
100
200
Ls = 113 Ls = 142
Ls~93-97
OMEGA: Modes 2 and 3 in NPC sublimation marked by 1.25 m water ice band depth
MGCM water column, pr µm
Ls~113-115 Ls~127-136
Ls~94 Ls~114 Ls ~132
The location of maximal wind stress at the NPC coincides with spots of enhanced ice aging
0 5
Near-surface wind according to MGCM (m/s)
Ls = 92 Ls = 113 Ls = 137
+
+
+
+
+
(!) NPC sublimation rate depends on dynamics of the ambient atmosphere, not just heating and relative humidity
Ls = 145 event: switching from mesoscale to global perturbation
Ls = 92 Ls = 137 Ls = 147
Zonal flow meridional shear
Meridional V-component Emerging circumpolar vortex
Wave-3 pattern
-5 5 -10 10-5 5
Decaying circumpolar vortex
Polar vortex barotropic instability: laboratory studies (Barbosa et al., 2010)
Mode 3 in the residual seasonal water ice deposits (left) and MGCM moisture (right)
MEX/OMEGA 1.5 m indexRodin et al., 2010 MGCM
South hemisphere Ls = 225 event: implications to dust cycle
Ls = 220 Ls = 227
Near-surface dust mixing ratio (ppm)
Wave-3 pattern
0 50
Ls = 233
Wave-2 pattern Wave-4 pattern
0 50 0 50
Season of the strongest transient in the South hemisphere coincides with thewindow of dust storm initiation
Conclusions
• The nature of current Mars water cycle is understood; GCMs are able to reproduce observables
• The role of polar caps, regolith, and clouds needs further quantitative assessment
• Water cycle demonstrates a major role of low-wavenumber eddy transport in the Martian atmopsheric circulation